Semiconductor Devices

Abstract

To suppress the occurrence of the detachment of a sealing member to a cooling plate.SOLUTION: In a semiconductor device 10, a cooling plate 60 has a convex shape with respect to a front surface S and includes an engagement part 61 including engagement surfaces 61a, 61b inclined at an acute angle to the front surface S. When such an engagement part 61 is also sealed by a sealing member 75, engaging surfaces 61a, 61b have an anchoring effect on a sealing member 75. Thereby, the occurrence of peeling of the sealing member 75 from the cooling plate 60 is suppressed. Thus, a reduction in the reliability of the semiconductor device 10 is prevented.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a semiconductor device. [Background technology]

[0002] The semiconductor device includes a power device and is used as a power conversion device. Examples of the power device include an IGBT (Insulated Gate Bipolar Transistor) and a power MOSFET (Metal Oxide Semiconductor Field Effect Transistor). The semiconductor device includes a semiconductor chip including the power device, which is arranged on a metal cooling plate, and an insulating circuit board housed in a case, and the inside of the case is sealed with a sealing member. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-115297 Summary of the Invention [Problem to be solved by the invention]

[0004] Temperature cycles cause stress in semiconductor devices due to differences in the linear expansion coefficients of the components that make up the semiconductor device. Large stresses occur, particularly at the interface between the cooling plate and the sealing member. This can cause the sealing member to peel off from the cooling plate. When the sealing member peels off, moisture can seep in through the peeled area. This can cause the insulation of the semiconductor chip, insulating circuit board, and other components to be compromised.

[0005] The present invention has been made in view of the above points, and has an object to provide a semiconductor device in which the occurrence of peeling of the sealing member from the cooling plate is suppressed. [Means for solving the problem]

[0006] According to one aspect of the present invention, there is provided an insulating circuit board including a semiconductor chip, an insulating plate, a circuit pattern formed on the front surface of the insulating plate and to which the semiconductor chip is bonded, and a metal plate formed on the back surface of the insulating plate, a cooling plate to which the insulating circuit board is bonded via a bonding member, a case bonded in an annular shape to an outer edge portion of the front surface of the cooling plate via an adhesive along the outer edge and surrounding the semiconductor chip and the insulating circuit board, and a sealing member for sealing the semiconductor chip and the insulating circuit board on the cooling plate within the case, wherein the cooling plate has a protruding portion with respect to the front surface of the cooling plate. The letter and an engagement surface inclined at an acute angle with respect to the front surface of the cooling plate, the engagement surface having a joining portion including a first engagement surface facing the insulating circuit board, the first engagement surface being located in a region of the cooling plate facing an end of the insulating plate of the insulating circuit board in a side view. [Effects of the Invention]

[0007] According to the disclosed technique, peeling between the sealing member and the cooling plate can be prevented, and a decrease in the reliability of the semiconductor device can be suppressed. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a side cross-sectional view of a semiconductor device according to a first embodiment. [Figure 2] 1 is a plan view of a semiconductor device according to a first embodiment. [Figure 3] 1 is a side cross-sectional view of a main part of a semiconductor device according to a first embodiment. [Figure 4] FIG. 10 is a diagram of a coupling portion included in a semiconductor device according to a modified example 1-1 of the first embodiment. [Figure 5] FIG. 10 is a plan view of a semiconductor device according to a modified example 1-2 of the first embodiment. [Figure 6] FIG. 10 is a plan view of a semiconductor device according to a modified example 1-3 of the first embodiment. [Figure 7] 10 is a plan view (part 1) of a semiconductor device according to a modification 1-4 of the first embodiment. FIG. [Figure 8] FIG. 10 is a plan view (part 2) of the semiconductor device according to Modification 1-4 of the first embodiment. [Figure 9] FIG. 10 is a cross-sectional side view of a main part of a semiconductor device according to a second embodiment. [Figure 10] FIG. 10 is a cross-sectional side view of a main part of a semiconductor device according to a modified example 2-1 of the second embodiment. [Figure 11] FIG. 10 is a cross-sectional side view of a main part of a semiconductor device according to a third embodiment. [Figure 12] FIG. 11 is a side cross-sectional view of a main part of a cooling plate included in a semiconductor device according to a third embodiment. [Figure 13] FIG. 13 is a diagram showing a coupling portion included in a semiconductor device according to a modification 3-1 of the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments will be described with reference to the drawings. In the following description, the terms "front surface" and "upper surface" refer to the surface facing upward in the semiconductor device 10 of FIG. 1. Similarly, "up" refers to the upward direction in the semiconductor device 10 of the drawings. The terms "back surface" and "lower surface" refer to the surface facing downward in the semiconductor device 10 of the drawings. Similarly, "lower" refers to the downward direction in the semiconductor device 10 of the drawings. Similar directions will be used in other drawings as necessary. The terms "front surface," "upper surface," "upper," "back surface," "lower surface," "lower," and "side surface" are merely convenient expressions for specifying relative positional relationships and do not limit the technical concept of the present invention. For example, "upper" and "lower" do not necessarily refer to the vertical direction relative to the ground. In other words, the "upper" and "lower" directions are not limited to the direction of gravity.

[0010] [First embodiment] A semiconductor device according to a first embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a side cross-sectional view of the semiconductor device according to the first embodiment, and FIG. 2 is a plan view of the semiconductor device according to the first embodiment. Note that FIG. 1 is a cross-sectional view of a portion corresponding to the dashed dotted line Y1-Y1 in FIG. 2. Also, in FIG. 2, the sealing member 75 of the semiconductor device 10 is not shown.

[0011] As shown in FIG. 1, semiconductor device 10 includes insulating circuit boards 20a and 20b and a cooling plate 60 to which insulating circuit boards 20a and 20b are attached via solder 23 (see FIG. 3). As shown in FIG. 2, semiconductor chips 30a, 30b, 40a, and 40b are directly bonded to insulating circuit boards 20a and 20b via solder (not shown). Semiconductor device 10 also includes a case 70 (frame portion 70a) that is attached to the periphery of cooling plate 60 via adhesive 76 and surrounds insulating circuit boards 20a and 20b. Lead frames 71, 72, and 73 are attached to case 70 (lid portion 70b). One end of lead frame 71 is directly (electrically and mechanically) connected to insulating circuit board 20a, and the other end is exposed to case 70 as terminal 71a. One end of lead frame 72 is directly connected to insulating circuit board 20b, and the other end is exposed as terminal 72a to case 70. One end of lead frame 73 is directly connected to insulating circuit board 20a, and the other end is exposed as terminal 73a to case 70. Insulating circuit boards 20a and 20b inside case 70 are sealed with sealing member 75.

[0012] Insulated circuit boards 20a and 20b are rectangular in plan view. Furthermore, as shown in Figures 1 and 2, insulated circuit boards 20a and 20b include insulating plates 21a and 21b, circuit patterns 22a1-22a3 and 22b1-22b3 formed on the front surfaces of insulating plates 21a and 21b, and metal plates 23a and 23b formed on the back surfaces of insulating plates 21a and 21b. The shapes and numbers of circuit patterns 22a1-22a3 and 22b1-22b3 are merely examples.

[0013] The insulating plates 21a and 21b are rectangular in plan view. The corners of the insulating plates 21a and 21b may be chamfered. For example, the corners may be C-chamfered or R-chamfered. The insulating plates 21a and 21b are made of ceramics with good thermal conductivity. The ceramics may be made of a material containing aluminum oxide, aluminum nitride, or silicon nitride as a main component, for example. The thickness of the insulating plates 21a and 21b is 0.2 mm or more and 2.0 mm or less.

[0014] Circuit patterns 22a1-22a3 and 22b1-22b3 are formed over the entire surfaces of insulating plates 21a and 21b, excluding their edges. Preferably, in a plan view, the ends of circuit patterns 22a1-22a3 and 22b1-22b3 facing the outer periphery of insulating plates 21a and 21b overlap the ends of metal plates 23a and 23b on the outer periphery of insulating plates 21a and 21b. This maintains a stress balance between insulating circuit boards 20a and 20b and metal plates 23a and 23b on the back surfaces of insulating plates 21a and 21b. Damage to insulating plates 21a and 21b, such as excessive warping and cracking, is suppressed. The squares in circuit patterns 22a2, 22b2, and 22a3 represent connection areas for lead frames 71, 72, and 73.

[0015] The circuit pattern 22a1 is U-shaped in plan view and is formed in the center of the end (-X direction side) of the insulating plate 21a. The opening of the circuit pattern 22a1 faces the +X direction. The circuit pattern 22a2 is U-shaped in plan view and is formed in the center of the insulating plate 21a. An opening that opens in the +X direction is formed at the end (+X direction side) of the circuit pattern 22a2. Furthermore, a protrusion that protrudes in the -X direction is formed at the end (-X direction side) of the circuit pattern 22a2. The opening of the circuit pattern 22a1 fits into this protrusion of the circuit pattern 22a2. One end of the lead frame 71 is joined to the -X direction side of the circuit pattern 22a2. The circuit pattern 22a3 is T-shaped in plan view and is formed at the end (+X direction side) of the insulating plate 21a. The circuit pattern 22a3 is formed within the opening of the circuit pattern 22a2. The protruding portion of the circuit pattern 22a3 is exposed in the +X direction from the opening of the circuit pattern 22a2. One end of the lead frame 73 is joined to the +X direction side of the circuit pattern 22a3.

[0016] The circuit pattern 22b1 is I-shaped in plan view and is formed in the center of the end (+X direction side) of the insulating plate 21b, spanning the ±Y directions of the insulating plate 21b. The circuit pattern 22b2 is T-shaped in plan view and is formed adjacent to the circuit pattern 22b1 on the insulating plate 21b. The circuit pattern 22b2 also protrudes in the −X direction. The circuit pattern 22b3 is U-shaped in plan view and is formed in the center of the end (−X direction side) of the insulating plate 21b. One end of the lead frame 72 is joined to the protruding portion of the circuit pattern 22b2. The opening of the circuit pattern 22b3 faces the +X direction. The protruding portion of the circuit pattern 22b2 fits into the opening of the circuit pattern 22b3.

[0017] The thickness of the circuit patterns 22a1-22a3 and 22b1-22b3 is 0.1 mm or more and 2.0 mm or less. The circuit patterns 22a1-22a3 and 22b1-22b3 are made of a metal with excellent conductivity. Such a metal is, for example, copper, aluminum, or an alloy containing at least one of these. The surfaces of the circuit patterns 22a1-22a3 and 22b1-22b3 may be plated to improve corrosion resistance. Examples of plating materials used in this case include nickel, nickel-phosphorus alloy, and nickel-boron alloy. The circuit patterns 22a1-22a3 and 22b1-22b3 for the insulating plates 21a and 21b are obtained by forming a metal plate on the front surfaces of the insulating plates 21a and 21b and then etching the metal plate. Alternatively, circuit patterns 22a1-22a3 and 22b1-22b3 cut out from a metal plate in advance may be pressure-bonded to the front surfaces of insulating plates 21a and 21b. Note that circuit patterns 22a1-22a3 and 22b1-22b3 are merely examples. The number, shape, size, etc. of the circuit patterns may be selected appropriately as needed.

[0018] The metal plates 23a and 23b are rectangular in plan view. The corners may be chamfered. For example, C-chamfering or R-chamfering may be used. The metal plates 23a and 23b are smaller than the insulating plates 21a and 21b and are formed on the entire back surfaces of the insulating plates 21a and 21b, excluding the edges. The metal plates 23a and 23b are primarily composed of a metal with excellent thermal conductivity. The metal may be, for example, copper, aluminum, or an alloy containing at least one of these. The thickness of the metal plates 23a and 23b is 0.1 mm or more and 2.0 mm or less. The metal plates 23a and 23b may be plated to improve their corrosion resistance. Examples of plating materials used in this case include nickel, a nickel-phosphorus alloy, and a nickel-boron alloy.

[0019] Insulated circuit boards 20a, 20b having such a configuration may be, for example, DCB (Direct Copper Bonding) boards or AMB (Active Metal Brazed) boards. Insulated circuit boards 20a, 20b can dissipate heat generated in semiconductor chips 30a, 30b, 40a, 40b by conducting it to the lower side in FIG. 1 via circuit patterns 22a2, 22b2, insulating plates 21a, 21b, and metal plates 23a, 23b.

[0020] The semiconductor chips 30a, 30b, 40a, and 40b include power device elements made of silicon, silicon carbide, or gallium nitride. The thickness of the semiconductor chips 30a, 30b, 40a, and 40b is, for example, 40 μm or more and 250 μm or less. The semiconductor chips 30a and 30b, which are power device elements, are switching elements, and the semiconductor chips 40a and 40b are diode elements. The semiconductor chips 30a and 30b, which are switching elements, are, for example, IGBTs and power MOSFETs. Such semiconductor chips 30a and 30b each have, for example, a drain electrode (or collector electrode) as a main electrode on the back surface and a gate electrode and a source electrode (or emitter electrode) as a control electrode and a main electrode on the front surface, respectively.

[0021] The semiconductor chips 40a and 40b, which are diode elements, are, for example, Schottky Barrier Diodes (SBDs) or Free Wheeling Diodes (FWDs) of P-intrinsic-N (PiN) diodes. Each of the semiconductor chips 40a and 40b has a cathode electrode as a main electrode on the back surface and an anode electrode as a main electrode on the front surface.

[0022] Alternatively, a reverse-conducting (RC) IGBT, which has both the functions of an IGBT and an FWD, may be used for the semiconductor chips 30a, 30b, 40a, and 40b. In this case, the semiconductor chip has an output electrode serving as an emitter electrode and a control electrode serving as a gate electrode on the front surface, and an input electrode (not shown) serving as a collector electrode on the back surface.

[0023] The following wires 50 are wired to the insulating circuit boards 20a, 20b and semiconductor chips 30a, 30b, 40a, 40b. In FIGS. 1 and 2, wires 50 are used to refer to all wires connecting components other than the control wiring. Wires 55a, 55b, which are control wiring, are electrically connected to the circuit patterns 22a1, 22b1 and the gates of the semiconductor chips 30a, 30b, respectively. The other wires 50 electrically connect the semiconductor chips 30a, 30b, the semiconductor chips 40a, 40b, and the circuit patterns 22a3, 22b3 as appropriate. The wires 50, 55a, 55b are made of highly conductive metals such as aluminum or copper, or alloys containing at least one of these metals. Their diameters are preferably 100 μm or more and 1.00 mm or less.

[0024] The lead frames 71, 72, and 73 are primarily composed of a material with excellent electrical conductivity. Examples of such materials include aluminum, iron, silver, copper, or an alloy containing at least one of these. The surfaces of the lead frames 71, 72, and 73 may be plated to improve corrosion resistance. Examples of plating materials used include nickel, nickel-phosphorus alloy, and nickel-boron alloy. One end of the lead frame 71 is directly bonded to the circuit pattern 22a2, and the other end is exposed from the end (negative X-direction side) of the lid portion 70b. One end of the lead frames 72 and 73 is directly bonded to the circuit patterns 22b3 and 22a3, and the other end is exposed from the end (positive X-direction side) of the lid portion 70b. One end of the lead frames 71, 72, and 73 is bonded to the circuit patterns 22a2, 22b3, and 22a3 by solder (not shown). Direct bonding may be achieved by laser welding or ultrasonic bonding instead of soldering.

[0025] All of the solders described above are lead-free solders. Lead-free solders are primarily composed of alloys containing at least two of tin, silver, copper, zinc, antimony, indium, and bismuth. Furthermore, the solder may contain additives, such as nickel, germanium, cobalt, or silicon. The inclusion of additives in the solder improves the wettability, gloss, and bonding strength, thereby improving reliability. Alternatively, a metal sintered compact may be used. Examples of the metal used in the metal sintered compact include silver and silver alloys.

[0026] The cooling plate 60 has a rectangular shape in a plan view. The thickness of the cooling plate 60 is 0.5 mm or more and 5.0 mm or less, for example, approximately 1.0 mm. The cooling plate 60 is primarily composed of a metal with excellent thermal conductivity. The metal may be, for example, copper, aluminum, or an alloy containing at least one of these. The cooling plate 60 may be plated to improve its corrosion resistance. Examples of plating materials used in this case include nickel, nickel-phosphorus alloy, and nickel-boron alloy. The back surfaces of the metal plates 23a and 23b of the insulating circuit boards 20a and 20b are joined to the front surface S of the cooling plate 60 with solder 23 (see FIG. 3). The solder 23 in this case may be as described above or may be a sintered metal.

[0027] Furthermore, a joint 61 is formed on the front surface S of the cooling plate 60. The joint 61 is formed continuously in an annular shape along the frame 70a of the case 70 on the front surface of the cooling plate 60. The joint 61 surrounds the insulating circuit boards 20a and 20b. That is, the joint 61 is formed between the frame 70a of the case 70 and the outer edges of the insulating circuit boards 20a and 20b in a side view. The corners of the joint 61, which is annular in a plan view, may be rounded. The details of the joint 61 will be described later.

[0028] A cooler 65 can be attached to the backside of the cooling plate 60 via solder, brazing material, or thermal interface material to improve heat dissipation. The cooler 65 is primarily composed of a material with excellent thermal conductivity, such as aluminum, iron, silver, copper, or an alloy containing at least one of these. The cooler 65 can also be a heat sink with fins or multiple fins, or a water-cooled cooling device. The cooling plate 60 can also be integrally formed with the cooler 65. In this case, the cooler 65 is composed of aluminum, iron, silver, copper, or an alloy containing at least one of these materials, which have excellent thermal conductivity. A plating process can be performed to improve corrosion resistance. Examples of plating materials used in this case include nickel, nickel-phosphorus alloys, and nickel-boron alloys.

[0029] The brazing filler metal is primarily composed of at least one of aluminum alloy, titanium alloy, magnesium alloy, zirconium alloy, and silicon alloy. When using brazing filler metal, it can be joined to a predetermined area on the back surface of the cooling plate 60 by brazing. Thermal interface material is a general term for various materials, such as thermally conductive grease, elastomer sheet, RTV (Room Temperature Vulcanization) rubber, gel, and phase change material. Grease is, for example, silicone mixed with a metal oxide filler.

[0030] The case 70 includes a frame 70a and a lid 70b. The frame 70a is annular in plan view. The frame 70a has inner wall surfaces 70a1, 70a2, 70a3, and 70a4, which sequentially surround a storage area 70a5. The frame 70a is provided along the outer edge of the cooling plate 60, surrounding the insulating circuit boards 20a and 20b via an adhesive 76. The adhesive 76 is primarily composed of an organic adhesive. The organic adhesive has a heat resistance temperature of approximately 100°C to 200°C. Specifically, the adhesive 76 is an epoxy-, silicone-, or acrylic-based adhesive. The adhesive 76 may be in either a paste or sheet form. The lid 70b is attached to the frame 70a, covering the opening of the frame 70a. The other ends of the lead frames 71, 72, and 73 are exposed through the lid 70b.

[0031] Such a case 70 is made of resin. This resin is mainly composed of a thermoplastic resin. Examples of the thermoplastic resin include polyphenylene sulfide resin, polybutylene terephthalate resin, polybutylene succinate resin, polyamide resin, and acrylonitrile butadiene styrene resin. Such a resin is filled into a predetermined mold, solidified, and the mold is removed to form the frame portion 70a. Similarly, the lid portion 70b is formed separately from the frame portion 70a. Note that the lid portion 70b may be formed by setting the lead frames 71, 72, and 73 in a predetermined mold, filling the mold with resin, and solidifying the resin. In this way, the lid portion 70b and the lead frames 71, 72, and 73 are integrally molded.

[0032] The sealing member 75 seals the inside of the case 70 to a height sufficient to seal the insulating circuit boards 20a, 20b, the semiconductor chips 30a, 30b, 40a, 40b, the wires 50, and the lead frames 71, 72, 73 inside the case 70. At this time, the sealing member 75 also seals the coupling portion 61, as described below. The sealing member 75 contains a thermosetting resin and a filler contained in the thermosetting resin as a filler. Examples of the thermosetting resin include epoxy resin, phenolic resin, and maleimide resin. Examples of the filler include glass, silicon dioxide, aluminum oxide, boron nitride, and aluminum nitride. An example of such a sealing member 75 contains an epoxy resin and a filler. The filler is at least one of the fillers described above.

[0033] Next, details of coupling portion 61 will be described with reference to Figure 3. Figure 3 is a side cross-sectional view of a main portion of the semiconductor device according to the first embodiment. Note that Figure 3 shows an enlarged view of the periphery of coupling portion 61 on the inner wall surface 70a2 side of frame portion 70a in the side cross-sectional view of Figure 1. Here, coupling portion 61 for insulating circuit board 20b will be described, but the same applies to insulating circuit board 20a.

[0034] The joint 61 may be surrounded by multiple sides. ,cold The coupling portion 61 includes engagement surfaces 61a and 61b (corresponding to the first and second engagement surfaces, respectively) that are convex with respect to the front surface S of the cooling plate 60 and are inclined at an acute angle with respect to the front surface S. Note that it is sufficient that at least one of the engagement surfaces 61a and 61b of the coupling portion 61 is inclined. Figure 3 shows a case where the engagement surfaces 61a and 61b are inclined at the same angle (inclination angle α) with respect to the front surface S of the cooling plate 60.

[0035] The cross section of the connecting portion 61 has engagement surfaces 61a and 61b that are inclined relative to the front surface S of the cooling plate 60, forming an inverted trapezoid shape. An inverted trapezoid is a trapezoid whose upper base is longer than its lower base. The engagement surfaces 61a and 61b of the connecting portion 61 connect the upper and lower bases.

[0036] The engagement surface 61a faces the insulating circuit board 20b, and the engagement surface 61b (the side of the coupling portion 61) faces the inner wall surface 70a2 of the frame portion 70a. The engagement surfaces 61a and 61b are each inclined at an inclination angle α with respect to the front surface of the cooling plate 60. This inclination angle α is preferably 45° or more and 80° or less. The coupling portion 61 has an inverted trapezoidal shape because the inclination angles α of the engagement surfaces 61a and 61b are equal. The inclination angles α of the engagement surfaces 61a and 61b may be different as long as they are acute angles. In this case, the cross section of the coupling portion 61 is not necessarily inverted trapezoidal.

[0037] The connection points (corners in side view) between the engagement surfaces 61a, 61b and the upper base may be C-chamfered or R-chamfered. Similarly, the connection points (corners in side view) between the engagement surfaces 61a, 61b and the lower base may be C-chamfered or R-chamfered. In particular, by forming the connection points with the lower base as C-chamfered or R-chamfered, when the joint portion 61 is sealed with the sealing member 75, as described below, the sealing member 75 is more likely to fill the deepest part of the connection points without leaving any voids. This prevents a decrease in the adhesion of the sealing member 75 to the joint portion 61. Furthermore, the upper base does not necessarily have to be parallel to the lower base. The upper base may be, for example, arc-shaped or have irregularities.

[0038] The height of the coupling portion 61 may be lower than the position of the insulating plate 21b of the insulating circuit board 20b joined to the cooling plate 60 with the solder 23. The width of the (upper base of) the coupling portion 61 in the X direction may be approximately the same as the height of the coupling portion 61.

[0039] The joint 61 may be formed on the front surface S of the cooling plate 60 between the solder 23 of the insulating circuit board 20b and the frame portion 70a (adhesive 76). By forming the joint 61 between them, the effect of the joint 61, which will be described later, can be similarly obtained. In the first embodiment, the joint 61 is formed on the front surface S of the cooling plate 60 closer to the insulating circuit board 20b than to the frame portion 70a. Specifically, the joint 61 is formed on the front surface S of the cooling plate 60, closer to the insulating circuit board 20b than to the frame portion 70a. Z When the area of ​​the cooling plate 60 corresponding to the direction of the engagement surface 61a is defined as point P, the engagement surface 61a is and planar viewThe joining portion 61 is formed on the front surface S of the cooling plate 60 so as to correspond to (be located at) point P. The joining portion 61 is also formed on the front surface S of the cooling plate 60 so that point P overlaps the upper surface of the joining portion 61 (corresponding to the engagement surface 61a) in a plan view.

[0040] Furthermore, the joining portion 61 is not limited to the engagement surface 61a, and the engagement surface 61b may also be formed on the front surface S of the cooling plate 60 so as to overlap with point P in side and plan views. The joining portion 61 only needs to be formed such that the engagement surface 61b overlaps with the board end (corresponding to point P) of the insulating circuit board 20b (insulating plate 21b) between the frame portion 70a (adhesive 76) in side view.

[0041] Such a connecting portion 61 is joined to a predetermined position on the cooling plate 60 by, for example, brazing. The connecting portion 61 may be made of the same material as the cooling plate 60 or a different material. The material of the connecting portion 61 can be selected so as to have good adhesion to the sealing member 75.

[0042] When the sealing material 75 is filled onto the cooling plate 60 having such a bonding portion 61 formed on the front surface S, the sealing material 75 seals the bonding portion 61 and then solidifies. The semiconductor device 10 generates stress due to differences in the linear expansion coefficients of the components that make up the semiconductor device 10 due to temperature cycles. In particular, stress tends to concentrate at corners within the case 70. This combined stress may cause the sealing material 75 to peel off from the cooling plate 60 and even stretch.

[0043] In this case, in the semiconductor device 10, the engagement surfaces 61a and 61b of the coupling portion 61 sealed by the sealing member 75 are inclined, thereby providing an anchor effect to the sealing member 75. In other words, the inclined engagement surfaces 61a and 61b of the coupling portion 61 restrain the sealing member 75 from peeling in the +Z direction in the -Z direction. The coupling portion 61 engages with the sealing member 75 via the engagement surfaces 61a and 61b. In particular, the coupling portion 61 of the semiconductor device 10 is formed to include the four corners of the cooling plate 60 inside the case 70. Therefore, in the semiconductor device 10, peeling of the sealing member 75 from the cooling plate 60 is suppressed. The coupling portion 61 also blocks the peeling of the sealing member 75 from extending in the ±X directions. To prevent peeling of the sealing member 75, such coupling portion 61 may be formed in an open area of ​​the cooling plate 60 on which the insulating circuit boards 20a and 20b are mounted. The coupling portion 61 does not necessarily have to be continuous and may be a dashed line. Alternatively, a plurality of coupling portions 61 may be formed so as to extend from the inner wall surfaces 70a1 to 70a4 of the case 70 toward the insulating circuit boards 20a and 20b.

[0044] As described above, the coupling portion 61 is formed on the front surface S of the cooling plate 60 so that the engagement surface 61a corresponds to (is located at) point P of the cooling plate 60. If the engagement surface 61a is closer to the insulating circuit board 20b than point P, the gap between the insulating circuit board 20b and the coupling portion 61 (engagement surface 61a) becomes narrower, and the sealing member 75 may not be sufficiently filled. In this case, there is a risk that the insulating properties of the insulating circuit board 20b may be reduced and the adhesion between the sealing member 75 and the coupling portion 61 may be reduced.

[0045] Furthermore, if the joint 61 is formed on the front surface S of the cooling plate 60 closer to the frame 70a than to the insulating circuit board 20b, if the sealing member 75 peels off between the joint 61 and the insulating circuit board 20b, the peeling may extend toward the insulating circuit board 20b, which may result in peeling of the solder 23.

[0046] The semiconductor device 10 includes semiconductor chips 30a, 30b, 40a, and 40b, insulating circuit boards 20a and 20b, a cooling plate 60, a case 70, and a sealing member 75. The insulating circuit boards 20a and 20b are formed by insulating plates 21a and 21b and the front surfaces of the insulating plates 21a and 21b. On the surface The cooling plate 60 includes circuit patterns 22a1-22a3, 22b1-22b3 to which the semiconductor chips 30a, 30b, 40a, and 40b are bonded, and metal plates 23a and 23b formed on the back surfaces of the insulating plates 21a and 21b. The cooling plate 60 has the insulating circuit boards 20a and 20b bonded to its front surface S via solder 23. The case 70 is bonded in an annular shape to the outer edge of the front surface S via adhesive 76, and surrounds the semiconductor chips 30a, 30b, 40a, and 40b and the insulating circuit boards 20a and 20b. The sealing member 75 seals the semiconductor chips 30a, 30b, 40a, and 40b and the insulating circuit boards 20a and 20b on the cooling plate 60 within the case 70. Furthermore, in the semiconductor device 10, the cooling plate 60 has a coupling portion 61 that is convex with respect to the front surface S and includes engagement surfaces 61a, 61b that are inclined at an acute angle with respect to the front surface S. When such coupling portion 61 is sealed with the sealing member 75, the engagement surfaces 61a, 61b have an anchor effect on the sealing member 75. This prevents the sealing member 75 from peeling off from the cooling plate 60. This prevents a decrease in the reliability of the semiconductor device 10.

[0047] Such a connecting portion 61 may have at least an engagement surface that is inclined relative to the front surface S of the cooling plate 60. Various modified examples of the connecting portion 61 that include such an engagement surface will be described below.

[0048] (Variation 1-1) Various modified examples of the coupling portion 61 will be described with reference to FIG. 4. FIG. 4 is a diagram of the coupling portion included in the semiconductor device in Modification 1-1 of the first embodiment. Note that FIG. 4 shows cross-sectional views of the coupling portion 61 corresponding to FIG. 3. The coupling portion 61 in FIGS. 4(A) to 4(G) may be continuously formed in a ring shape along the frame portion 70a on the front surface S of the cooling plate 60, as shown in FIG. 2.

[0049] The coupling portion 61 shown in FIGS. 4A to 4G has at least one engagement surface that is inclined at an acute angle with respect to the front surface S of the cooling plate 60. The coupling portion 61 in FIG. 4A has a shape similar to two of the coupling portions 61 in FIG. 3, with one of them inverted upside down and the other placed on top of it. That is, the coupling portion 61 in FIG. 4A has a trapezoidal lower portion and an inverted trapezoidal upper portion. In this case, it has a pair of engagement surfaces 61a, 61b. The coupling portion 61 in FIG. 4B also has a shape similar to two of the coupling portions 61 in FIG. 3 that are inclined upside down. In this case, both the upper and lower portions of the coupling portion 61 have inverted trapezoidal shapes. Therefore, the coupling portion 61 in FIG. 4B has two pairs of engagement surfaces 61a, 61b. The coupling portion 61 in FIG. 4B has a larger area that is inclined with respect to the front surface S of the cooling plate 60 (the engagement area with the sealing member 75) than the coupling portion 61 in FIG. 3. Therefore, it is possible to more reliably prevent the sealing member 75 from peeling off from the cooling plate 60 than in the case of Fig. 3. Note that in the joint portion 61 of Fig. 4(B), the inclination angle α of the upper engagement surfaces 61a, 61b and the inclination angle α of the lower engagement surfaces 61a, 61b do not necessarily have to be equal.

[0050] 4(C) to 4(E) include an engagement surface 61a and a side portion 61a1 facing the engagement surface 61a. The coupling portion 61 in FIG. 4(C) has a rectangular shape including the engagement surface 61a on only one side. The coupling portion 61 in FIG. 4(D) has a shape similar to two coupling portions 61 in FIG. 4(C), one of which is inverted upside down and the other is stacked on top of it. That is, the lower portion of the coupling portion 61 in FIG. 4(D) has a shape similar to that of FIG. 4(C) inverted, and the upper portion has a shape similar to that of FIG. 4(C). The coupling portion 61 in FIG. 4(E) has a shape similar to two coupling portions 61 in FIG. 4(C) stacked on top of each other. Note that the inclination angle α of the upper engagement surface 61a of the coupling portion 61 in FIG. 4(E) does not necessarily have to be equal to the inclination angle α of the lower engagement surface 61a. 4(C) to 4(E), the side portion 61a1 extends perpendicular to the front surface S of the cooling plate 60. That is, the side portion 61a1 may be at an angle of 90° with respect to the front surface S of the cooling plate 60. Also, the left and right sides of each of FIGS. 4(C) to 4(E) may be reversed.

[0051] The coupling portion 61 in FIG. 4(F) is rhombic. That is, the coupling portion 61 in FIG. 4(F) includes one engagement surface 61a and a side portion 61a1 facing the engagement surface 61a. The coupling portion 61 in FIG. 4(G) is triangular. That is, the coupling portion 61 in FIG. 4(G) also includes one engagement surface 61a. The engagement surface 61a in FIG. 4(F) is inclined at an inclination angle α. The side portion 61a1 facing the engagement surface 61a, shown in FIGS. 4(F) and 4(G), is inclined at an inclination angle β with respect to the front surface S of the cooling plate 60. In this case, the inclination angle β is an obtuse angle.

[0052] (Variation 1-2) In Modification 1-2, a case in which the coupling portion 61 is formed in a ring-shaped broken line on the front surface S of the cooling plate 60 surrounded by the case 70 will be described with reference to Fig. 5. Fig. 5 is a plan view of a semiconductor device in Modification 1-2 of the first embodiment. Note that Fig. 5 corresponds to the plan view of Fig. 2, and is the same as the semiconductor device 10 of the first embodiment except for the coupling portion 61.

[0053] A joint portion 61 is also formed on the front surface S of the cooling plate 60 of the semiconductor device 10a, which is surrounded by the case 70. In this case, the joint portion 61 is formed in a ring-shaped broken line on the front surface S of the cooling plate 60.

[0054] As described above, the semiconductor device 10a is susceptible to stress concentration, particularly at corners within the case 70, due to differences in the linear expansion coefficients of the components constituting the semiconductor device 10a during temperature cycles. Therefore, the dashed-line joints 61 preferably include at least portions formed at corners of the front surface S of the cooling plate 60, which is surrounded by the case 70. The joints 61 may be formed on the long and short sides of the cooling plate 60, as appropriate, as long as they are formed at least at the corners. The adjacent sides of the dashed-line joints 61 are also sealed with the sealing member 75. Furthermore, in addition to the engagement surfaces 61a and 61b, the adjacent sides of the dashed-line joints 61 may also be inclined at an acute angle relative to the front surface S of the cooling plate 60. When sealed with the sealing member 75, the inclined sides, in addition to the engagement surfaces 61a and 61b, provide an anchor effect to the sealing member 75. This more effectively prevents the sealing member 75 from peeling off from the cooling plate 60.

[0055] (Variation 1-3) In Modification 1-3, a case where coupling portions 61 are formed at the four corners of insulating circuit boards 20a, 20b of semiconductor device 10 shown in Figures 1 and 2 will be described with reference to Figure 6. Figure 6 is a plan view of a semiconductor device in Modification 1-3 of the first embodiment. Note that Figure 6 corresponds to the plan view of Figure 2, and is the same as semiconductor device 10 of the first embodiment except for coupling portions 61 and insulating plates 21a, 21b.

[0056] In the semiconductor device 10a, the four corners of the insulating plates 21a and 21b of the semiconductor device 10 are chamfered. For example, these may be C-chamfered. A joint 61 is formed in each of the four chamfered corner regions of the insulating plates 21a and 21b in a plan view. However, one joint 61 is formed between each of the adjacent corners of the insulating plates 21a and 21b. It is sufficient that the joint 61 is formed at least in the corners of the insulating plates 21a and 21b facing the corner of the case 70.

[0057] In particular, the coupling portion 61 formed at the corner of the case 70, which is the corner of the insulating plates 21a, 21b, includes at least one of the engagement surfaces 61a, 61b. Furthermore, the coupling portion 61 may be formed so that the engagement surfaces 61a, 61b face the corner of the case 70 or the chamfered corner of the insulating plates 21a, 21b.

[0058] As described above, in this semiconductor device 10a, stress is also likely to concentrate at the corners of the case 70, making it easy for the sealing member 75 to peel off at these corners. In the semiconductor device 10a of FIG. 6, joints 61 are formed at least at the corners of the case 70, which are the chamfered corners of the insulating plates 21a and 21b. In the semiconductor device 10a, these joints 61 prevent the sealing member 75 from peeling off at the corners of the case 70. Furthermore, in the semiconductor device 10a, the joints 61 can be formed in the chamfered areas of the insulating plates 21a and 21b. This makes it possible to reduce the size of the semiconductor device 10a while preventing the sealing member 75 from peeling off.

[0059] (Variation 1-4) In Modification 1-4, the joint 61 formed when the case 70 is divided into multiple sections will be described with reference to Figs. 7 and 8. Figs. 7 and 8 are plan views of a semiconductor device in Modification 1-4 of the first embodiment. Note that in Figs. 7 and 8, only components necessary for the description are labeled. For the components included in the semiconductor device 10b, reference can be made to Figs. 1 and 2.

[0060] The case 70 of the semiconductor device 10b shown in FIGS. 7 and 8 is divided into three storage areas 70a6, 70a7, and 70a8 along the X direction. The semiconductor device 10b has an insulating circuit board disposed in each of the storage areas 70a6, 70a7, and 70a8 of the divided case 70. As described above, in the semiconductor device 10b, stress tends to concentrate particularly at the corners of the case 70 due to temperature cycles caused by differences in the linear expansion coefficients of the components constituting the semiconductor device 10b. For this reason, the semiconductor device 10b shown in FIG. 7 has coupling portions 61 formed at the corners of each of the storage areas 70a6, 70a7, and 70a8. Note that, in this case, as in Modification 1-2, the coupling portions 61 may be formed in dashed lines along the long and short sides of the storage areas 70a6, 70a7, and 70a8 in addition to the corners.

[0061] 8, the coupling portions 61 are formed only at the corners of the entire case 70. In this case, too, the coupling portions 61 are not limited to the corners, and may be formed in the form of dashed lines at locations along the long and short sides of the cooling plate 60, as in Modification 1-2.

[0062] 7 and 8, in addition to the engagement surfaces 61a and 61b, the adjacent side surfaces may also be inclined at an acute angle with respect to the front surface S of the cooling plate 60, as described in Modification 1-2.

[0063] [Second embodiment] In the second embodiment, a case where the engagement surface 61b (side portion) of the coupling portion 61 is close to the case 70 will be described with reference to FIG. 9. FIG. 9 is a side cross-sectional view of a main portion of the semiconductor device in the second embodiment. The semiconductor device 10c of the second embodiment has the same configuration as the semiconductor device 10 of the first embodiment, except for the coupling portion 61. FIG. 9 corresponds to the cross-sectional view of FIG. 3.

[0064] The coupling portion 61 of the semiconductor device 10c is formed on the front surface S of the cooling plate 60 between the insulating circuit board 20b and the frame portion 70a of the case 70. The coupling portion 61 includes an engagement surface 61a and an engagement surface 61b (side portion) opposite the engagement surface 61a. Furthermore, the width of the coupling portion 61 in the X direction is longer than the width of the coupling portion 61 of the first embodiment. As in the first embodiment, the engagement surface 61a is provided at a position corresponding to point P in a side view. The engagement surface 61b is provided in close proximity to the inner wall surface 70a2 of the frame portion 70a. Note that this proximity range is 0.8 to 1.2 times the height of the coupling portion 61 from the inner wall surface 70a2 of the frame portion 70a.

[0065] Alternatively, the engagement surface 61b may be in contact with the inner wall surface 70a2 of the frame portion 70a. That is, in a side view, the upper end of the engagement surface 61b in the +Z direction (the side opposite to the front surface S of the cooling plate 60) is in contact with the inner wall surface 70a2 of the frame portion 70a, and the joining portion 61 is formed on the front surface S of the cooling plate 60. The upper end of the engagement surface 61b corresponds to the arrangement area of ​​the frame portion 70a in a plan view. join The engaging surface 61b functions as a positioning element when attaching the frame 70a. On the other hand, the lower end of the engaging surface 61b in the -Z direction (on the front surface side of the cooling plate 60) may be located within five times the thickness of the adhesive 76 from the inner wall surface 70a2 of the frame 70a. This makes it possible to prevent the adhesive 76 from spilling out, as will be described later.

[0066] The height of the joint 61 is the length in the direction perpendicular to the front surface S of the cooling plate 60 (+Z direction). As in the first embodiment, this height of the joint 61 is lower than the insulating plate 21b of the insulating circuit board 20b. Furthermore, this height may be higher than the thickness of the adhesive 76.

[0067] Although the engagement surface 61b is inclined as in the first embodiment, it may be perpendicular to the front surface S of the cooling plate 60. That is, the engagement surface 61b may be substantially parallel to the inner wall surface 70a2 of the frame portion 70a. Note that, as in the first embodiment, such a coupling portion 61 is also formed continuously in an annular shape on the front surface S of the cooling plate 60, which is surrounded by the case 70.

[0068] Now, consider a case where the joining portion 61 is not provided. In the semiconductor device 10c, when the case 70 (frame portion 70a) is attached to the cooling plate 60 via adhesive 76, the adhesive 76 that bonds the frame portion 70a and the cooling plate 60 may protrude somewhat toward the storage area 70a5. If the inside of the case 70 is sealed with a sealing member 75 while the adhesive 76 is protruding, the protruding portion of the adhesive 76 is also sealed by the sealing member 75. However, the protruding portion of the adhesive 76 may become the starting point for peeling of the sealing member 75. Peeling of the sealing member 75 may extend from the inner wall surface 70a2 of the frame portion 70a to the insulating circuit board 20b. If the peeling extends further, it may reach the solder 23, causing the solder 23 to peel off.

[0069] Therefore, in the semiconductor device 10c, the coupling portion 61 is formed on the cooling plate 60. This coupling portion 61 provides an anchoring effect for the sealing member 75, similar to the first embodiment. As a result, peeling of the sealing member 75 from the cooling plate 60 is prevented. Furthermore, the engagement surface 61b of the coupling portion 61 is located close to the inner wall surface 70a2 of the frame portion 70a. Therefore, the extension of peeling from the protruding portion of the adhesive 76 from the inner wall surface 70a2 of the frame portion 70a of the sealing member 75 to the insulating circuit board 20b is suppressed near the frame portion 70a. Since the extension of peeling of the sealing member 75 is suppressed, peeling of the solder 23 is also suppressed. Furthermore, since the engagement surface 61b is located close to the inner wall surface 70a2 of the frame portion 70a, significant overflow of the adhesive 76 is suppressed. This also prevents the occurrence of peeling starting points for the sealing member 75.

[0070] (Variation 2-1) In Modification 2-1, another modification of the second embodiment will be described with reference to Fig. 10. Fig. 10 is a side cross-sectional view of a main part of a semiconductor device in Modification 2-1 of the second embodiment. The semiconductor device 10d of Modification 2-1 also has the same configuration as the semiconductor device 10 of the first embodiment, except for the coupling portion 61.

[0071] In the semiconductor device 10d, another coupling portion 61 is formed outside the coupling portion 61 in the same manner as in the semiconductor device 10 of the first embodiment. The engagement surface 61b of the outer another coupling portion 61 is close to the inner wall surface 70a2 of the frame portion 70a, as in the second embodiment. The engagement surface 61b of the another coupling portion 61 may be perpendicular to the front surface S of the cooling plate 60 without being inclined. The inclination angles of the engagement surfaces 61a, 61b of the coupling portion 61 and the another coupling portion 61 may be different. The heights of the coupling portion 61 and the another coupling portion 61 may be different.

[0072] In the semiconductor device 10d, as in the second embodiment, the extension of peeling from the protruding portion of the adhesive 76 from the inner wall surface 70a2 of the frame portion 70a of the sealing member 75 to the insulating circuit board 20b can be suppressed in the vicinity of the frame portion 70a. Also, the semiconductor device 10d has a greater number of bonding portions 61 than the first embodiment. This increases the engagement area with the sealing member 75, thereby reliably preventing peeling of the sealing member 75 from the front surface S of the cooling plate 60.

[0073] [Third embodiment] In the third embodiment, a case where the coupling portion 61 is concave rather than convex will be described with reference to FIGS. 11 and 12. FIG. 11 is a side cross-sectional view of a main part of a semiconductor device in the third embodiment. FIG. 12 is a side cross-sectional view of a main part of a cooling plate included in the semiconductor device in the third embodiment. A semiconductor device 10e of the third embodiment is the semiconductor device 10 of the first embodiment, with the coupling portion 61 formed in a concave shape. Other configurations are the same as those of the semiconductor device 10 of the first embodiment. Also, FIG. 11 corresponds to the cross-sectional view of FIG. 3.

[0074] The connecting portion 61 is concave with respect to the front surface S of the cooling plate 60 and includes engagement surfaces 61a, 61b that are inclined at an acute angle with respect to the front surface S. At least one of the engagement surfaces 61a, 61b of the connecting portion 61 needs to be inclined. FIG. 11 shows a case where the engagement surfaces 61a, 61b are inclined at the same angle (inclination angle α) with respect to the front surface S of the cooling plate 60. The cross section of the connecting portion 61 is trapezoidal because the engagement surfaces 61a, 61b are inclined with respect to the front surface S of the cooling plate 60.

[0075] The engagement surface 61a faces the inner wall surface 70a2 of the frame portion 70a within the opening, and the engagement surface 61b faces the insulating circuit board 20b. The engagement surfaces 61a and 61b are each inclined at an inclination angle α with respect to the front surface of the cooling plate 60. This inclination angle α is preferably 45° or more and 80° or less. The coupling portion 61 has a trapezoidal shape because the inclination angles α of the engagement surfaces 61a and 61b are equal. However, the inclination angles α of the engagement surfaces 61a and 61b may be different as long as they are acute angles. In this case, the cross section of the coupling portion 61 is not limited to a trapezoidal shape.

[0076] The connection points (corners) between the engagement surfaces 61a, 61b and the bottom surface may be C-chamfered or R-chamfered. By having the connection points with the bottom surface be C-chamfered or R-chamfered, when the joint portion 61 is sealed with the sealing member 75, as described below, the sealing member 75 fills the connection points deep inside without leaving any voids. This prevents a decrease in the adhesion of the sealing member 75 to the joint portion 61. Furthermore, the bottom surface does not necessarily have to be parallel to the front surface S (XY plane) of the cooling plate 60. The bottom surface may be arc-shaped or have irregularities formed thereon.

[0077] The depth of the joint 61 may be 0.2 to 0.5 times the thickness of the cooling plate 60. The width of the joint 61 (lower base) in the X direction may be 1.0 to 5.0 times the depth of the joint 61.

[0078] The coupling portion 61 is formed on the front surface S of the cooling plate 60 closer to the insulating circuit board 20b than the frame portion 70a. Z If the area of ​​the cooling plate 60 corresponding to the direction (the direction of the cooling plate 60) is defined as point P, the connecting portion 61 is formed on the front surface S of the cooling plate 60 so that the engagement surface 61a corresponds to point P in a side view. In addition, the concave connecting portion 61 may be formed instead of the convex connecting portion 61 shown in Figures 2 and 5 to 8.

[0079] Such a coupling portion 61 can be formed, for example, as follows. First, a flat cooling plate 60a and cooling plates 60b1 and 60b2, each having tapered surfaces formed by tapering to correspond to the engagement surfaces 61a and 61b, are prepared in advance. The cooling plate 60a has a rectangular shape in plan view. The cooling plate 60b1 has a smaller rectangular shape than the cooling plate 60a in plan view. The cooling plate 60b2 has a frame shape in plan view and is large enough to surround the cooling plate 60b1.

[0080] As shown in Fig. 12, cooling plate 60b1 is placed on the front surface of cooling plate 60a. Then, cooling plate 60b2 is placed on cooling plate 60a with a predetermined gap between the engagement surface 61b of cooling plate 60b2 and the engagement surface 61a of cooling plate 60b1. Note that cooling plates 60b1 and 60b2 are joined to cooling plate 60a by brazing. In this way, cooling plate 60 with concave joint portion 61 is formed.

[0081] When the sealing material 75 is filled into the cooling plate 60 having the joint portion 61 formed on the front surface S in this manner, the sealing material 75 seals the joint portion 61 and then solidifies. In the semiconductor device 10e, the inclined engagement surfaces 61a and 61b of the joint portion 61 sealed in the sealing material 75 provide an anchor effect for the sealing material 75. That is, the inclined engagement surfaces 61a and 61b of the joint portion 61 restrain the sealing material 75 from peeling in the -Z direction, even if the sealing material 75 attempts to peel in the +Z direction. The joint portion 61 engages with the sealing material 75 through the engagement surfaces 61a and 61b. In particular, the joint portion 61 of the semiconductor device 10e is also formed to include the four corners of the cooling plate 60 inside the case 70. Therefore, in the semiconductor device 10e, peeling of the sealing material 75 from the cooling plate 60 is suppressed. Note that, to prevent peeling of the sealing material 75, such joint portions 61 may be formed in the open areas of the cooling plate 60 on which the insulating circuit boards 20a and 20b are mounted. Furthermore, the connecting portion 61 does not necessarily have to be continuous in a ring shape, but may be in the form of a broken line. Alternatively, the connecting portion 61 may be formed in a plurality of ring shapes, such as double or triple layers.

[0082] (Variation 3-1) Various modified examples of the joints 61 will be described with reference to FIG. 13. FIG. 13 is a diagram of a joint included in a semiconductor device in Modification 3-1 of the third embodiment. Note that FIG. 13 shows cross-sectional views of the joints 61 corresponding to FIG. 11. Each joint 61 in FIG. 13 is formed continuously in a ring shape or in a dashed line shape along the frame portion 70a on the front surface S of the cooling plate 60.

[0083] The coupling portion 61 shown in FIGS. 13(A) to 13(E) is formed in a concave shape by etching on the front surface S of the cooling plate 60. The coupling portion 61 shown in FIGS. 13(A) to 13(E) has at least one engagement surface that is inclined at an acute angle in side view. The coupling portion 61 in FIG. 13(A) is formed in a concave shape including engagement surfaces 61a and 61b in side view. The coupling portion 61 in FIG. 13(B) has a shape similar to two of the coupling portions 61 in FIG. 13(A) stacked on top of each other. Therefore, the coupling portion 61 in FIG. 13(B) has two pairs of engagement surfaces 61a and 61b. The coupling portion 61 in FIG. 13(B) has a larger area that is inclined with respect to the front surface S of the cooling plate 60 (the engagement area with the sealing member 75) than the case in FIG. 13(A). Therefore, it is possible to more effectively prevent the sealing member 75 from peeling off from the cooling plate 60 than in the case of Fig. 13(A). Note that in the joint 61 of Fig. 13(B), the inclination angle α of the upper engagement surfaces 61a, 61b and the inclination angle α of the lower engagement surfaces 61a, 61b do not necessarily have to be equal.

[0084] 13(C) to 13(E) include an engagement surface 61a and a side portion 61a1 facing the engagement surface 61a. The coupling portion 61 in FIG. 13(C) is rectangular and includes an engagement surface 61a on only one side. In FIG. 13(C), the side portion 61a1 extends perpendicular to the front surface S of the cooling plate 60. That is, the side portion 61a1 may be at an angle of 90° with respect to the front surface S of the cooling plate 60. The coupling portion 61 in FIG. 13(D) is diamond-shaped. That is, the coupling portion 61 in FIG. 13(D) includes one engagement surface 61a and a side portion 61a1 facing the engagement surface 61a. The coupling portion 61 in FIG. 13(E) is triangular-shaped. That is, the coupling portion 61 in FIG. 13(E) also includes one engagement surface 61a. 13(D) and 13(E) are inclined at an inclination angle α. The side portions 61a1 in FIGS. 13(D) and 13(E) are inclined at an inclination angle β with respect to the front surface S of the cooling plate 60. In this case, the inclination angle β is an obtuse angle. Also, the left and right sides of FIGS. 13(C) to 13(E) may be reversed. [Explanation of symbols]

[0085] 10, 10a, 10b, 10c, 10d, 10e semiconductor device 20a, 20b Insulated circuit board 21a, 21b Insulating plate 22a1~22a3, 22b1~22b3 Circuit pattern 23a,23b Metal plate 23 Solder 30a, 30b, 40a, 40b Semiconductor chips 50, 55a, 55b Wire 60,60a,60b1,60b2 Cooling plate 61 Joint 61a,61b Engagement surface 61a1 Side 65 Cooler 70 cases 70a Frame 70a1, 70a2, 70a3, 70a4 Inner wall surface 70a5, 70a6, 70a7, 70a8 Storage area 70b Lid 71, 72, 73 Lead frame 71a, 72a, 73a terminals 75 Sealing member 76 Adhesive S front

Claims

1. A semiconductor chip; an insulating circuit board including an insulating plate, a circuit pattern formed on a front surface of the insulating plate to which the semiconductor chip is bonded, and a metal plate formed on a rear surface of the insulating plate; a cooling plate having a front surface to which the insulating circuit board is bonded via a bonding member; a case that is annularly bonded to an outer periphery of the front surface of the cooling plate via an adhesive along the outer periphery, and that surrounds the semiconductor chip and the insulating circuit board; a sealing member that seals the semiconductor chip and the insulating circuit board on the cooling plate inside the case; Equipped with the cooling plate includes an engagement surface that is convex with respect to a front surface of the cooling plate and inclined at an acute angle with respect to the front surface of the cooling plate, the engagement surface having a coupling portion that includes a first engagement surface facing the insulating circuit board; the first engagement surface is located in a region of the cooling plate facing an end of the insulating plate of the insulating circuit board in a side view; Semiconductor device.

2. the joint portion is formed between the joining member and the case on the front surface of the cooling plate in a side view. The semiconductor device according to claim 1 .

3. The coupling portion has a side portion on the opposite side of the first engagement surface, and the side portion is formed between the region of the cooling plate and the case in a plan view. The semiconductor device according to claim 2 .

4. The engagement surface of the coupling portion includes a second engagement surface facing the case.

3. The semiconductor device according to claim 1.

5. an upper end of the second engagement surface opposite to the front surface of the cooling plate contacts the inner wall surface of the case; The semiconductor device according to claim 4 .

6. a lower end of the second engagement surface on the front surface side of the cooling plate is located within five times the thickness of the adhesive from the inner wall surface of the case; The semiconductor device according to claim 5 .

7. a height of the second engagement surface from the front surface of the cooling plate on the case side equal to or greater than the thickness of the adhesive and lower than the insulating plate; The semiconductor device according to claim 5 .

8. The joint portion is formed on the cooling plate along the case in a plan view.

8. The semiconductor device according to claim 1.

9. The joint portion is formed continuously in a ring shape along the case on the cooling plate in a plan view. The semiconductor device according to claim 8 .

10. The joint portion is formed in a broken line shape along the case on the cooling plate in a plan view. The semiconductor device according to claim 8 .

11. The joint portion includes a portion formed at a corner portion of the case of the cooling plate in a plan view.

11. The semiconductor device according to claim 7.

12. a corner of the insulating circuit board facing the corner of the case is chamfered in a plan view; the coupling portions are formed in the chamfered areas of the insulating circuit board on the front surface of the cooling plate, respectively. The semiconductor device according to claim 1 .

13. The inclination angle of the first engagement surface is 45° or more and 80° or less with respect to the front surface of the cooling plate. The semiconductor device according to claim 1 .

14. The joint portion is joined to the front surface of the cooling plate by brazing. The semiconductor device according to claim 1 .

15. a height of the joint portion from the front surface of the cooling plate being higher than the thickness of the adhesive and lower than the insulating plate of the insulating circuit board; The semiconductor device according to claim 1 .

Images